Moisture and density gauge

Abstract

A moisture and density gauge which combines sources of gamma and neutron radiation in a casing which is placed in the medium being analyzed. The gauge includes detectors for the gamma and neutron radiation being placed in end to end configuration within the casing such that the neutron detector is placed between the gamma radiation detector and the source of gamma radiation.

What is claimed is: 
     
       1. A moisture and density gauge for a medium having, in combination, a source of gamma radiation, a source of neutron radiation, and means for receiving signals and transforming the received signals into a representation of the moisture and density of the medium, the improvement comprising: a. a casing, the gamma radiation and neutron radiation sources being placed in said casing, said casing intended for being placed in the medium;   b. means for detecting and signaling the gamma radiation emanating from the source of gamma radiation after interaction with the medium, said means for detecting and signaling the emanation of gamma radiation being placed in said casing;   c. means for detecting and signaling the neutron radiation from said source of neutron radiation after interaction with the medium, said means for detecting and signaling the radiation of neutrons after interaction with the medium being placed in said casing between said means for detecting and signaling the gamma radiation and the source of gamma radiation, said signals representing the detected neutron and gamma radiation being transmitted to the means for receiving signals.   
     
     
       2. The moisture and density gauge of claim 1 which additionally comprises a gamma radiation shield placed within said casing and substantially surrounding the source of gamma radiation, said gamma radiation shield including an aperture. 
     
     
       3. The moisture and density gauge of claim 1 which includes means for placing the source of neutron radiation immediately adjacent the source of gamma radiation. 
     
     
       4. The moisture and density gauge of claim 1 which includes means for placing the source of neutron radiation adjacent said means for detecting and signaling the radiation of neutrons. 
     
     
       5. The moisture and density gauge of claim 1 in which said means for detecting and signaling the gamma radiation emanation includes a Geiger-Mueller tube. 
     
     
       6. The moisture and density gauge of claim 1 in which said means for detecting the radiation of neutrons includes a boron trifluoride tube. 
     
     
       7. The moisture and density gauge of claim 1 in which said means for detecting the radiation of neutrons includes a helium three tube. 
     
     
       8. The moisture and density gauge of claim 1 which additionally comprises means for amplifying said signals from said means for detecting and signaling the gamma radiation and neutron radiation from the sources, said amplifying means being located within said casing. 
     
     
       9. A method for simultaneously obtaining moisture and density readings in a medium comprising the steps of: a. placing a neutron radiation detector in a casing between a source of gamma radiation and a gamma radiation detector;   b. placing a source of neutron radiation within the casing at substantially the same level in the casing as the source of gamma radiation;   c. lowering the casing into the medium to a certain depth;   d. transmitting said signals to the vicinity of the surface of the medium;   e. transforming said signals into a measure of the moisture and density of the medium.